The present invention relates to a lamp device and a lamp assembly including such a lamp device useful in suppressing electro-magnetic interference and directing light as desired. The present invention particularly relates to such a lamp device and lamp assembly useful in connection with a vehicle.
The lamp device and lamp assembly of the present invention is illustrated herein with reference to a lamp for use with a motor vehicle. However, it will be apparent to those skilled in the art that the present invention is not limited to such an application.
The use of a motor vehicle stop lamp is well known. One of the concerns regarding such a lamp is providing a lamp which satisfactorily directs a beam of light during use. Another concern is the desire to substantially reduce of eliminate any electro-magnetic interference created by the lamp. These concerns are particularly troublesome when low pressure discharge lamps are considered as the source of light. Low pressure discharge lamps such as conventional neon lamps are very efficient sources of light. However, such lamps are diffuse sources of light which makes a directed beam of light difficult to achieve. Low pressure discharge lamps are also sources of electro-magnetic interference created as the lamp discharge extends across the discharge cavity. Electro-magnetic interference is particularly undesirable when present in an automobile due to the presence of various electronic devices operating in the vehicle, including without limitation a radio. For example, electro-magnetic interference tends to interfere with the reception of the radio.
Various efforts have been made to eliminate electro-magnetic interference in automotive lamp applications. For example, different types of grounding schemes have been attempted with varying degrees of success. One attempt has involved applying Indium Tin Oxide on glass or plastic surfaces associated with the automotive lamp. However, it is difficult to apply Indium Tin Oxide to glass or plastic, and such application tends to be very expensive. Another attempt has involved the use of screen mesh with the lens of an automotive lamp. However, the use of screen mesh is not without problems, the assembly of a lamp using screen mesh being very difficult. For example, it is difficult to assemble the screen mesh in a uniform manner on the lamp or contouring inside lenses. Such problems tend to increase the cost of the lamp. During use of the lamp, the screen mesh greatly reduces light output.
It is an object of the present invention to provide an improved lamp device and lamp assembly.
Another object of the present invention is to provide an improved lamp device and lamp assembly which obviates the disadvantages of the prior art.
Yet another object of the present invention is to provide an improved lamp device and lamp assembly which provides the required directed beam of light.
A further object of the present invention is to provide an improved lamp device and lamp assembly which provides little or no electro-magnetic interference during use thereof.
Another object of the present invention is to provide an improved lamp device and lamp assembly useful in providing a very efficient light source.
A further object of the present invention is to provide an improved lamp device and lamp assembly which may be readily fabricated relatively inexpensively.
Yet another object of the present invention is to provide an improved lamp device and lamp assembly the use of which does not substantially reduce light output.
Another object of the present invention is to provide an improved lamp device and lamp assembly useful with a low pressure discharge lamp.
It is still another object of the present invention to provide an improved lamp device and lamp assembly useful as a vehicular lamp.
This invention achieves these and other objects by providing a lamp device, comprising, a light transmissive light bar structured and arranged for coupling a lamp thereto. The light bar comprises an input surface, an output surface and a body segment extending therebetween. The body segment is structured and arranged for reflection therein of, and collection of electro-magnetic interference emitted by, light projected through the light bar by the lamp from the input surface to the output surface.
A low pressure discharge lamp assembly comprising such a lamp device is also provided. In particular, a light transmissive light bar is provided having an input surface, an output surface and a body segment extending therebetween. The body segment is structured and arranged for reflection therein of, and collection of electro-magnetic interference emitted by, light projected through the light bar from the input surface to the output surface. A low pressure discharge lamp is coupled to the light bar adjacent the input surface. The lamp is structured and arranged to project light through the light bar from the input surface to the output surface.